Barrage lines up with the aoe ooze phase and should be better than glaive toss because of this. If the timing is off, fix it. Waiting a few seconds for a lot more targets is a gain than just using it on two.

To get your pet onto the conveyor belt: Keep your pet on passive. Force pet to attack Blackfuse each time before getting in/on the pipe. Press pet passive again when you land on the belt and it should teleport to your side.

Although clunky, a glyphed Explosive Trap could help knock the adds back into the Iron Star on the Garrosh Fight.

I also wonder if it would be beneficial to pick up Powershot for this fight for the knockback in phase 1. I know a Druid's Typhoon or a Demo Lock's Carrion Swarm would probably be better than any Hunter using a knockback. But hey, every bit counts.